Congressional midterm elections were held in the United States in November 2010. Midterm cycles have historically been unkind to the party of the incumbent president, which has on average lost 24 seats in the U.S. House and 4 seats in the U.S. Senate in midterms during the postwar era. In the 2010 general elections, Democrats, who had enjoyed unified control of the federal government since January 2009, suffered devastating defeats in congressional, gubernatorial, and state legislative races nationwide. Democrats lost a total of 63 seats in the U.S House of Representatives—a loss greater than in any other midterm in the postwar period—relinquishing control to the GOP for the first time since 2007 and ushering in a new era of divided government in Washington. Republicans also made gains in the U.S. Senate, although Democrats ultimately retained control of the chamber by a narrow margin of 51 to 47 (two independents also caucus with the Democrats).

The results of the 2010 elections came as a surprise to some, given the virtual collapse of the Republican Party in the 2006 and 2008 elections and the enthusiasm that was stirred up by the election of Barack Obama in 2008. Obama began his term as president with high expectations, as well as high approval and popularity ratings, but Americans' attitudes toward the president and his party began to erode precipitously as the economy remained tenuous and Democrats failed to deliver the wholesale change Obama had promised during his campaign (Cohen and Panagopoulos Reference Cohen, Panagopoulos, Dowdle, van Raemdonck and Marantoforthcoming). The inherent tension between Obama's dual planks of “change,” suggesting a departure from Bush-era policies and an ideological shift toward the left, and a “post-partisan presidency,” implying a more centrist approach, required the president to pursue a difficult balancing act on the legislative front that ultimately dissatisfied both his core liberal constituency and moderate, independent-leaning voters (Cohen and Panagopoulos Reference Cohen, Panagopoulos, Dowdle, van Raemdonck and Marantoforthcoming).

Signs of trouble for Democrats appeared even prior to the midterm cycle; losses in key gubernatorial races in Virginia and New Jersey in November 2009, and in the contest to fill Ted Kennedy's vacant U.S. Senate seat in Massachusetts in January 2010—all states that Obama had carried in November 2008—provided tangible evidence that voters had soured on Democrats and the president. The prospects for victory in the 2010 general elections propelled Republican enthusiasm and deflated Democrats' hopes, resulting in a palpable enthusiasm gap between Democratic and Republican sympathizers. Against this backdrop, Republicans recruited formidable and well-financed challengers in districts and states across the country. Voters' intentions to support Democratic candidates for the U.S. House in 2010 continued to decline throughout the preceding year, in tandem with waning presidential approval and economic performance ratings (Panagopoulos Reference Panagopoulos2010).

Prognostications of significant Democratic losses were confirmed in November 2010. Exit polls revealed considerable voter frustration with the president and congressional leadership, as well as concerns about the economy and health care in particular. Relative to 2006, exit polls also showed sizable drops in support for Democratic contenders in U.S. House races in demographic groups across the board, but declines were especially acute in key subgroups of voters that are essential to the Democratic coalition, including women, Latinos, and independent voters (CNN 2010).

Overall, the 2010 election cycle was historic by several measures and typical by others. This symposium includes six articles that provide early scholarly assessments of the 2010 congressional election cycle and its implications for politics in the aftermath. In the first article, Alan Abramowitz discusses how the results of the 2010 elections are likely to affect the ideological composition of the 112th Congress, concluding that it is likely to be the most ideologically divided Congress of the past 60 years. Next, David Jones and Monika McDermott analyze public approval of Congress and its electoral effects, demonstrating that since the 2008 elections, Congress has been more salient to the American public than usual, making it easier than ever for voters to hold the party in charge accountable. The authors argue that congressional evaluations played a stronger than usual role in the 2010 elections.

One of the more significant developments of the 2010 cycle was the emergence of the Tea Party movement, on whose impact Christopher Karpowitz, Quin Monson, Kelly Patterson, and Jeremy Pope reflect. Ultimately, the authors conclude that the overall impact of the Tea Party was most pronounced in primaries in 2010 but modest in the general elections. The authors also suggest the need for time to sort out the relationship between the movement and the Republican Party.

Examination of other aspects of the 2010 elections facilitates speculation about the likely consequences for the political and electoral process. Michael McDonald discusses the outcomes of the midterm elections and their implications for the 2010 redistricting process that will ensue in the months ahead. Next, I examine voter turnout in the 2010 general elections and show that statewide levels of voter participation were generally influenced by the structure of electoral competition. Finally, Jeffrey Stonecash focuses on split-outcome U.S. House districts and the dilemma that these districts pose for their representatives in Congress.

The 2010 midterm election cycle will likely be remembered as a watershed event, at least regarding the midterms. This symposium is assembled to reflect on the 2010 elections and their implications and to situate the cycle in historical context and within the framework of extant research on electoral politics. The selections aim to demystify aspects of the elections and provide initial insights, analysis, and empirical evidence about the realities and implications of the outcomes of the historic cycle.